Administrator: Override and can use KnowlEDGE over Manager(s) and Contributor(s)
Manager: Override and can use KnowlEDGE over Contributor(s)
Contributor: Only able to use KnowlEDGE to their assigned Writer/Approver workflows. Once a Writer has chosen a KnowlEDGE
For more about roles feel free to check out this Help Article.